Mechanical lock means for foundry molding machine



June 4, 1968 G. J. JANKE ETAL 3,336,493

MECHANICAL LOCK MEANS FOR FOUNDRY MOLDING MACHINE 2 Sheets-Sheet 1 Filed July 7, 1965 4 g. i; a F "m MW G g N s W a m 2 I M MECHANICAL LOCK MEANS FOR FOUNDRY MOLDING MACHINE Filed July 7, 1965 June 4, 1968 (5.1. JANKE ETAL 2 Sheets-Sheet 2 I34 I26 I27 5 INVENTORS. GILBERT J. JANKE BY MRRENA. BLOWER dflnhfllw OMZQ ATTORNEYS United States Patent 0 MECHANICAL LOCK MEANS FOR FOUNDRY MOLDING MACHINE Gilbert J. Janke, Parma, and Warren A. Blower, Brecks= ville, Ohio, assignors to The Osborn Manufacturing Company, Cleveland, Ohio, a corporation of Ohio Filed July 7, 1965, Ser. No. 469,981 17 Claims. (Cl. 164-473) ABSTRACT OF THE DISQLOSURE A completely pneumatic overhead squeeze molding machine utilizing opposed pneumatic piston-cylinder assemblies, one for supporting a sand filled flask and the other for squeezing the sand with the squeeze pistoncylinder assembly having a larger effective area and thus exerting a greater force, and two forms of mechanical lock means for the supporting piston to hold the same during squeeze, one comprising radially movable pins and the other a rotatably movable spline ring.

This invention relates generally as indicated to a f undry molding machine and more particularly to a completely pneumatic overhead squeeze machine capable of ramming quickly and efliciently sand molds of uniform high hardness.

Heretofore, to obtain high pressure squeeze in a foundry molding machine, it has been required to employ either large diameter pneumatic squeeze pistons or high pressure hydraulic systems and both have proven to be costly, both in manufacture and maintenance. Moreover, in overhead squeeze machines, it is required firmly to support the sand filled mold box as the overhead squeeze head is moved thereagainst. Such firm support can be obtained by lowering the same filled mold box onto a firm or rigid support such as a jolt table, but this requires complex flask conveyor elevator sections as well as intricate draw mechanisms. Reference may be had to the patent to E. K. Hatch et al. No. 3,169,285, entitled, Overhead Squeeze Molding Machine, for an example of a high pressure squeeze molding machine utilizing such flask elevator and draw mechanisms.

Alternatively, the flask may be supported on a column of oil or hydraulic fluid with the fluid supply being blocked. Reference may be had to the copending application of Leon F. Miller et al., Ser. No. 252,644, entitled Molding Machine, filed Ian. 21, 1963, now Patent No. 3,205,-

542 for an example of a jolt-squeeze molding machine wherein the same filled mold box may be supported on an inelastic body of fluid. Hydraulic systems, however, are usually slow acting and expensive and the long stroke required to assemble the pattern, flask, and then further elevate to squeeze requires a substantial amount of fluid. It has accordingly been found economical to utilize shorter strokes both top and bottom with the bottom stroke assembling the pattern and flask and supporting the mold box thus formed for filling with sand and the subsequent jolt operation, while the top stroke then moves the squeeze head downwardly to engage the sand within the flask. These relatively shorter strokes can, of course, best be accomplished by a pneumatic system providing a completely pneumatic machine, but the problem then arises of attempting to support the sand filled flask on an elastic column of air as the overhead squeeze head moves against the sand. Since the lower stroke is necessarily the longer, the penumatic strokes working against each other cannot effectively ram a foundry mold to the uniform high hardness required Without limiting the retreat of one of the pneumatic strokes.

Patented June 4, i968 ice It is accordingly a principal object of the present invention to provide a completely pneumatic squeeze molding machine wherein a mechanical lock is employed in association with a pneumatic clamp piston to enable a high pressure overhead squeeze to be applied to the foundry sand.

A further object is the provision of an overhead squeeze molding machine utilizing a npeumatic stroke to assembly the flask and pattern and support the same for th jolt operation and the subsequent draw.

Another object is the provision of such pneumatic overhead squeeze molding machine incorporating a stroke locking mechanism to enable the application of a high pressure overhead squeeze.

A still further object is the provision of a jolt squeeze molding machine which is entirely pneumatically operated.

A yet further object is the provision of a pneumatic clamp piston assembly for foundry molding machines including a means to lock the same in elevated position.

Other objects and advantages of the present invention will become apparent as the following description proceeds.

To the accomplishment of the foregoing and related ends, the invention, then comprises the features hereinafter fully described and particularly pointed out in the claims, the following description and the annexed drawings setting forth in detail certain illustrative embodimerits of the invention, these being indicative, however, of but a few of the various Ways in which the principles of the invention may be employed.

In said annexe-d drawings:

FIG. 1 is a fragmentary side elevation of an overhead squeeze molding machine incorporating the features of the present invention;

FIG. 2 is an end elevation of the machine shown in FIG. 1 as seen from the right thereof;

FIG. 3 is a slightly enlarged vertical section of one form of base section which may be employed with the machine shown in FIGS. 1 and 2;

FIG. 4 is a horizontal section taken substantially on the line 4-4 of FIG. 3;

FIG. 5 is a vertical section similar to FIG. 3 taken substantially on the line 5--5 of FIG. 6 of another embodiment of the present invention;

FIG. 6 is a horizontal section taken substantially on the line 6-6 of FIG. 5.

Machine, general arrangement, FIGS. 1 and 2 Referring now to FIGS. 1 and 2 there is illustrated an overhead squeeze machine in accordance with the present invention which comprises a frame including a base 1 having four vertical posts or frame members 2, 3, 4 and 5 at each corner thereof. Transverse tie bars 6 and 7 join the frame members 2 and 5 and 3 and 4, respectively, at the top of the machine. Extending between the verticals 2 and 3, and 4 and 5, respectively, are plates 8 and 9, each having on the inside thereof a row of projecting rollers as shown at 10 and 11, respectively. In this manner the vertical frame members 2 through 5 are connected at the bottom by the base 1, and at the top by the transverse tie bars 6 and 7 as Well as the roller conveyor bars 8 and 9.

Mounted on the rows of rollers 10 and 11 are two interconnected carriages 13 and 14 which may be termed respectively, the squeeze-head carriage and the sand supply carriage. Such carriages may be interconnected by link shown generally at 15, and both are provided with laterally directed top flanges as indicated at 17 and 18 which overlie the rows of rollers 10 and 11. The underside of the edges of such flanges are provided with rails as seen at 19 and 20 in FIG. 1 supporting the carriage on the respective row of rollers. Each carriage may be provided with corner rollers as seen at 22 having their axes vertically disposed to engage and ride against the insides of the rails 8 and 9. In this manner both carriages are firmly supported by the conveyor rollers for horizontal shuttling movement back and forth at the top of the machine.

Such shuttling movement of the two carriages 13 and 14 is obtained by a pair of piston-cylinder assemblies shown at 24 and 25 mounted on brackets 26 and 27 on the vertical frame members 2 and 5, respectively. The rods 28 of the piston-cylinder assemblies are connected at 29 to brackets 30 extending downwardly from each side of the carriage 13. The extent of shuttling movement is limited by pairs of adjustable shock absorbers 31 and 32 which are operative to engage the stop plates or buttons 33 on lateral projections of the end plates as shown at 34 and 35 on the carriage 13. The stops 31 are mounted on L-shaped brackets 36 mounted on the ends of the rails 8 and 9, and the stops 32 are mounted on similar brackets 37. The carriage 13 also includes laterally projecting rails 38 and 39 which underlie the rails 8 and 9, respectively, preventing the carriage 13 from moving upwardly.

In the base there is provided an elevator or clamp cylinder 40 having a piston 41 therein operative to elevate table 42 having jolt table 43 mounted thereon by means of a jolt piston 44 telescoped within the clamp piston 41. Elevation of the table 42 and, of course, the jolt table 43 supported thereon will pick up a pattern stool 45 from pattern change conveyor 46. The latter is comprised of rails 47 and 48 having inwardly projecting rows of conveyor rollers 49 and 50, respectively. Continued elevation of the table 43 will pick up the pattern stool 45 from the conveyor 46 and the pattern stool 45 will then pick up a flask F from a flask conveyor 52. The latter is similarly comprised of rails 53 and 54 having inwardly projecting rows of rollers 55 and 56, thereon. Such rail 53 and 54 are mounted on brackets 57 and 58, respectively, extending between the vertical frame members 2 and 5, and 3 and 4, respectively.

The flask F may be in the form of a box, flanged both top and bottom, which will enclose the pattern P projecting upwardly from the pattern stool 45, and when thus assembled, the pattern and flask will form an upwardly opening mold box with the flask elevated slightly from the rollers 55 and 56. When the flask is thus positioned, the table 42 may be locked in its vertically elevated position by the locking mechanisms hereinafter described.

To fill the mold box with foundry molding sand, sand may be supplied from a vibratory feed conveyor, not shown, to the flared top 61 of measuring box 62 forming a part of the carriage 14. The bottom of the measuring box 62 is provided with horizontally pivoted louver gates 63 operated by horizontal movement of bar 64 which is in turn operated by piston-cylinder assembly 65 mounted on bracket 66. The rod 67 of the piston-cylinder assembly is pivoted at 68 to a toggle linkage 69. The linkage 69 is pivoted at 70 to the bracket 66 and at 71 to an intermediate link 72 pivoted at 73 to the operating bar 64.

The pivots 73, 71 and 70 form the three pivots ofthe toggle linkage with the pivot 71 moving slightly overcenter when the piston-cylinder assembly 65 is extended. This toggle linkage ensures that the louver gates 63 will remain closed regardless of the fluid pressure in the piston-cylinder assembly 65. When the piston-cylinder assembly 65 is retracted, the link 69 is pivoted upwardly about the pivot 70 and the toggle lock is broken moving the operating rod 64 to the right or horizontally as seen in FIG. 2, pivoting the louvers 63 to an open position to dump the sand within the measuring box into the chute 75. It will, of course, be appreciated that the carriage 14 will be shuttled to a position above the assembled mold box prior to the opening of the louver 63 by retraction of the piston-cylinder assemblies 24 and 25.

The chute 75 is provided with a bottom portion 76 telescope over the bottom of the chute and mounted on frame 77 which is pivoted at 78. A plow or strike-off blade 79 is provided on one end of the frame and the vertical position of the strike-oil blade may be adjusted by piston-cylinder assembly 80, the blind end thereof being pivoted at 81 to bracket 82, and the rod end being pivoted at 83 to the frame 77. After the carriage 14 is shuttled to a position over the flask F, the piston-cylinder assembly will be extended so that the lower portion 76 of the chute substantially completely encloses the space between the top of the flask F and the measuring box 62. After the sand is dumped within the flask, the pistoncylinder assembly 80 may be retracted and an adjustable stop 84 will control the vertical position of the strike-off blade 79 so that extension of the piston-cylinder assemblies 24 and 25 will then strike from the top of the flask any excess sand. The carriage 14 is then returned to its position beneath the vibratory feed conveyor and a measured amount of sand is then placed within the measuring box 62. The louvers, of course, at this time will be closed and the positioning of the carriage 14 as shown in FIG. 2 then places automatically the squeezehead carriage 13 above the now filled mold box.

Continued cycling of the machine will now operate the jolt mechanism, if desired, initially to compact the sand and the squeeze head within the carriage 13 may then be caused to descentd to obtain a high pressure final ramming of the sand within the flask against the pattern. When this is accomplished, the squeeze head is retracted, the table is unlocked and caused to descend depositing the flask F with the mold now rammed therein on the conveyor rollers 55 and 56, and continued lowering of the table draws the pattern P from the mold. The finished mold within the flask is then shuttled from the machine and a new flask is brought into position and the cycle is repeated. During the cycle, the pattern stool 45 may be lowered onto the pattern change conveyor 46 conveniently to effect a change in pattern.

The squeeze head which is illustrated broken away in FIG. 2 is shown in greater detail in applicants copending application entitled Foundry Molding Machine, filed even date herewith, and as illustrated may comprise a main upper frame 86 which includes the laterally projecting flanges 17 and a downwardly projecting cylindrical portion 87. A sliding seal 88 is mounted on the bottom of the portion 87 and provides a sliding seal with inner cylinder 89. Stepped guide rods 91 are fastened to the top web 93 of the member 86 and lock nuts 95 hold the shoulders of the rods against the bottom of the web 93. The inner cylinder 89 is provided with a web or piston portion 97 provided with packing glands 98 surrounding the enlarged polished portions of the rods 91 so that the piston 97 will be slide guided thereby. The lower ends of the rods 91 are also shouldered and secured to a fixed piston or partition 99 and piston rings or seals may be provided sealing the cylinder 89 within the cylinder 87 and the partition 99 within the cylinder 89, respectively. An end closure 104 which acts as a piston is mounted on the lower end of the cylinder 89 and the lower ends of the rods 91 extend through bushings 106 in the closure 104 and into partitioned chambers 107 in oil reservoir 109.

The chamber 110 in the reservoir 109 may be employed in a closed system to supply oil to a plurality of pistoncylinder assemblies 111 mounted on the bottom of the reservoir with the downwardly projecting piston rods 112 having squeeze feet or members 113 mounted thereon. Each of the piston-cylinder assemblies 111 is manifolded to the other so that as the squeeze head moves downwardly, the feet 113 will engage the top of the sand within the flask and the squeeze members will then retreat depending upon the resistance encountered. Reference may be had to the copending application of Edmond K. Hatch et al., Ser. No. 127,616, entitled Squeeze Molding Machine, now Patent No. 3,220,066, for a disclosure of the manner in which a plurality of such squeeze members 113 may be employed in a foundry molding machine. In this manner the high squeeze pressure obtained may be substantially uniformly distributed over the top of the mold sand and the members 113 over the portions of the mold having the greatest sand depth will penetrate furthest into the flask. To obtain vertical downward movement of the squeeze members 113 in turn to obtain a high pressure pneumatic squeeze, air may be supplied at approximately 100 pounds p.s.i. to the chambers above the piston 97 and above the end closure 104 which will cause the inner cylinder 89 to move downwardly within the outer cylinder 87. It will, of course, be appreciated that air may be supplied to one or the other of such chambers to obtain intermediate pressure squeezes. To elevate the squeeze members 113 air may be supplied at reduced pressure to the chamber beneath the piston 97 while the other two chambers are vented.

Table, FIG. 3 embodiment In order to support the sand filled mold box or flask F for the high pressure overhead squeeze, a jolt table such as shown in the FIG. 3 embodiment may be employed. The table 43 supporting the pattern stool 45 and the pattern P is mounted on a jolt piston 44 which is actually in the form of a downwardly projecting cylinder. The lower end of the cylinder 44 is supported in annular shoulder 120 of jolt ram 121 which is in turn supported on a large compression spring 122 within the upstanding cylindrical portion 123 of clamp piston 41. To elevate the clamp piston 41 air is supplied therebeneath to chamber 124 and to operate the jolt mechanism air may be supplied through port 126 in the jolt table 43 pressurizing the chamber 127.

Air pressure within the chamber 127 will cause the jolt table 43 to elevate and the jolt ram 121 to descend until the passage 128 in the ram is aligned with the exhaust passage 129 in the table 42. Downward movement of the ram 121 compresses the spring 122 and when the pressure in chamber 127 is thus relieved, the ram moves upwardly and the table 43 descends to obtain a jolt strike at the annular interface between the shoulder 120' and the bottom of the jolt piston or cylinder 44. A guide rod 131 extends between the two tables 43 and 42 and keeps the table 43 from rotating with respect to the table 42. The

rod may be fixed to the table 43 and extends through a bushing 132 in the table 42. Compensating springs 133 may be provided surrounding the guide rods 131 and there is also provided a sliding seal as shown at 134 between the cylinder 44 and the table 42 which is mounted on the top of the cylindrical portion 123 of the clamp piston 41.

The main clamp cylinder 40 surrounding the clamp piston is provided with top lateral projections shown at 136 which include bushings 137 surrounding guide rods 138 which are secured to the table 42. In this manner the table 42 is precluded from rotating with respect to the machine. A sliding seal 139 is provided at the top of the main cylinder 40 and a cylindrical liner 140 is incorporated between the main clamp cylinder 40 and the cylindrical portion 123 of the clamp piston 41.

As seen additionally in FIG. 4, a box type frame surrounds the main cylinder 40 and includes side plates 142 and 143 in which are mounted latch mechanisms 144 and 145, respectively. Such latch mechanisms include cylindrical housings 148 and 149 which are secured by fasteners 150 to lateral projections of the main clamp cylinder 40. Each cylindrical housing includes a cylindrical liner in which are slidably mounted locking pins 152 and 153. Each locking pin includes a chordal notch 154 and 155, respectively on the inner upper portions thereof having bottom horizontal surfaces. Movement of the locking pins toward and away from each other is obtained by piston-cylinder assemblies 156 and 157, respectively, which are mounted on end plates 158 on the housings 148 and the rods of such piston-cylinder assemblies are connected to the locking pins as indicated at 159.

In operation, air will be supplied to the chamber 124 beneath the clamp piston 41 through inlet port 160 passing into the chamber 124 by means of the clearance 161 between the clamp piston and clamp cylinder beneath the locking pins 152 and 153. Referring back to FIG. 2, the table 43 will then be elevated picking up the pattern stool and the pattern P from the pattern change conveyor 46 and further elevation will then pick up the flask F from the conveyor rollers and 56. The assembled pattern and flask forming the mold box will then be supported slightly elevated from the conveyor rollers 55 and 56.

With the sand measuring box 62 filled with sand from a source, not shown, the piston-cylinder assemblies 24 and 25 will be retracted to place the chute 75 above the now assembled mold box. The piston-cylinder assembly will operate the louver gates 63 then to dump the sand within the measuring box through the chute into the mold box. With the piston-cylinder assembly extended, the lower portion 76 of the sand chute substantially completely encloses the vertical space between the measuring box and the mold box. The piston-cylinder assembly 80 is now retracted to an adjusted position to fix the strike-off blade 79 and extension of the pistoncylinder assemblies 24 and 25 will return the carriages 13 and 14 to the position shown in FIG. 2. At this time air may be supplied to the port 126 to commence the jolt operation causing the ram 121 to descend and the table 43 to elevate until the ports 128 and 129 are aligned, then the spring 122 drives the ram upwardly and the table 43 descends by gravity to obtain the bottom strike jolt on the shoulder of the ram 121. This proceeds until the jolt operation is complete and after the jolt operation the double-acting piston-cylinder assemblies 156 and 157 may then be extended to cause the locking pins 152 and 153 to underlie the wear plates 163 and 164, respectively, on the bottom of the clamp piston 41. It is then apparent that the locking pins will limit the retreat of the clamp piston by the compression of the elastic medium or air within the chamber or column 124 beneath the clamp piston in its elevated position.

To obtain the high pressure overhead squeeze with the locking pins now in place, air is supplied to the chamber in the squeeze head above the piston 97 and to the chamber below the partition 99 to cause the squeeze members 113 to descend at high pressure against the top surface of the sand within the mold box. This will, of course, cause the clamp piston 41 to retreat, but such retreat will be limited by the inserted locking pins and the clamp piston and thus the mold box will be firmly held in its elevated position to receive the high pressure overhead squeeze.

When the squeezing operation is complete, air is supplied to the chamber subjacent the piston 97 in the squeeze head to elevate the same and the release of pressure on the flask will then slightly elevate the clamp piston 41 from the horizontal notches 154 and of the locking pins so that the piston-cylinder assemblies 156 and 157 may then be retracted. The table 43 now descends to place the mold and flask on the conveyor rollers 55 and 56 and further lowering of the table draws the pattern P from the flask. The flask with the finished mold therein is then shuttled from the machine and a new flask will be received to repeat the above-described operation.

FIG. 5 embodiment Referring now to FIGS. 5 and 6 there is illustrated another embodiment of the present invention utilizing a slightly diflerent mechanism for locking the table 43 in its elevated jolt position to receive the high pressure overhead squeeze. The tables 42 and 43 and the aligning end structures may be substantially identical to those illustrated in the FIG. 3 embodiment, and also the jolt piston 44 and ram 121 may be substantially the same. iowever, a slightly smaller diameter compression spring 170 is employed supporting the ram 121 at its lower end. The clamp piston 172 in which the compression spring 170 is seated includes an upper cylindrical portion 173 secured to the table 42 and a lower splined portion 174 with the splines 175 being shown more clearly in FIG. 6. To accommodate the clamp piston, the main clamp cylinder is comprised of upper and lower parts 177 and 178 with the upper part including a flange 179 seated on the top of the lower portion 178 which in turn includes a top flange 180 seated on the top of annular outer frame 181. Supported within shoulder 182 in the lower clamp cylinder frame portion 178 is a bearing ring 183 supporting for rotation thereon locking ring 184. The locking ring 184 internally is provided with notches 185 which in one rotative position thereof accommodate the splines 175. Rotation of the locking ring through a limited arc equal to approximately one-half the arcuate distance between the splines 175 is obtained by piston-cylinder assemblies 188 and 189 mounted on projections 190 and 191, respectively of the outer cylindrical housing 181. The rods U2. and 193- of the assemblies 188 and 189, respectively extend through seals 194 adjacent the recessed apertures accommodating the rods in the lower clamp cylinder portion 178. The rods are then connected at 195 and 19s to the locking ring with recesses 187 accommodating the rods. It can now be seen that extension of the piston-cylinder assembly 188 and retraction of the assembly 189 will cause the ring 184 to rotate to position the notches 186 in the phantom line position indicated at 198 when the splines 175 are vertically clear of such notches.

The operation of the FIG. embodiment will be the same with air being supplied to the chamber 200 beneath the clamp piston 172 causing the same to be elevated with the splines 175 moving within the notches 186. As soon as the splines vertically clear the locking ring 184, the same may be rotated to offset the notches thus providing a firm support beneath each of the splines on the main clamp piston. The locking ring may contact a Wear ring 201 mounted in the base of the clamp piston 1'72 and as the overhead squeeze head extends, the elastic medium and the chamber 200 will be compressed, but downward movement of the clamp piston will be limited by the locking ring 184. When the overhead squeeze is completed, the pressure in the chamber 200 will provide then a clearance between the ring and the wear plate or ring 201 and the locking ring may then be repositioned with the notches 186 aligined with the splines 175 so that the table may then be lowered to accomplish the draw operation.

It can now be seen that there is provided a completely pneumatic foundry molding machine obtaining high squeeze pressures with two opposed relatively short stroke pneumatic piston-cylinder assemblies. With a lock mechanism being employed to hold one of the assemblies in firm position while the other is driven thereagainst. In this manner a fast cycling high pressure yet economical foundry molding machine is provided.

Other modes of applying the principles of the invention may be employed, change being made as regards the details described, provided the features stated in any of the following claims or the equivalent of such be empi-oyeo.

We, therefore, particularly point out and distinctly claim as our invention:

1. A foundry molding machine comprising pneumatic piston cylinder means operative to assemble a pattern and flask to form a mold box, means to fill such box with molding sand, an squeeze piston assembly including a squeeze head operative to engage the sand within said box comprising a cylinder having a fixed partition therein, interconnected pistons on opposite sides of said partition, and means to supply fluid under pressure to said 8 pistons within said cylinder operative to urge said pistons in a common direction toward such molding sand, and means to support mechanically the piston of said pneu matic piston cylinder means mechanically to support the mold box for such squeeze operation.

2. in a foundry molding machine, a piston-cylinder pneumatically operated squeeze head, a piston-cylinder pneumatically operated table operative to assemble and support a sand filled mold box, lock means operative mechanically to hold one in firm position while the other is driven thereagainst, said lock means including a lock member, and means operative to move said lock member laterally of the path of movement of said table to hold the same in such firm position.

3. A foundry molding machine as set forth in claim 2 wherein said one is the pneumatically operated table and the other is the pneumatically operated squeeze head.

4. A foundry molding machine as set forth in claim 2 wherein the piston-cylinder pneumatically operated squeeze head has a substantially larger effective area than the piston-cylinder pneumatically operated table.

5. A foundry molding machine as set forth in claim 3 wherein the piston of said pneumatically operated table includes a splined portion, and said lock member includes a lock ring in one position accommodating said splined portion and in another position underlying the splines of said portion to lock said table in such firm position.

6. In a foundry molding machine, a piston-cylinder pneumatically operated squeeze head, a piston-cylinder pneumatically operated table operative to assemble and support a sand filled mold box, lock means operative mechanically to hold one in firm position while the other is driven thereagainst, said one being the pneumatically operated table and the other being the pneumatically operated squeeze head, said lock means comprising a lock pin, and means to extend and retract said pin from a position beneath the piston of said pneumatically operated table.

7. A foundry molding machine as set forth in claim 2 wherein said lock member includes a rotatable member coaxially disposed with the path of movement Of said table, and means operative to rotate said member to lock said table in such firm position.

8. A pneumatic foundry molding machine comprising a squeeze head at the top of said machine, a squeeze piston assembly operative to move said head downwardly, a table at the bottom of said machine, a clamp piston assembly operative to move said table upwardly, and mechanical lock means operative to engage and hold said clamp piston and thus said table in elevated position.

9. A pneumatic foundry molding machine as set forth in claim 8 wherein said mechanical lock means includes a notched ring interfitting with said clamp piston during the stroke thereof, and means operative to rotate said ring in the elevated position of said table to lock the same in such position.

10. A pneumatic foundry molding machine comprising a squeeze head at the top of said machine, a squeeze piston assembly operative to move said head downwardly, a table at the bottom of said machine, a clamp piston assembly operative to move said table upwardly, and lock means operative to hold said table in elevated position, said lock means comprising at least one lock pin laterally movable beneath said clamp piston assembly in such elevated position.

11. A pneumatic foundry molding machine comprising a squeeze head at the top of said machine, a squeeze piston assembly operative to move said head downwardly, a table at the bottom of said machine, a clamp piston assembly operative to move said table upwardly, lock means operative to hold said table in elevated position, said squeeze piston assembly comprising a cylinder having a fixed partition therein, interconnected pistons on opposite sides of said partition, and means to supply fluid under pressure to said pistons within said cylinder operative to urge said pistons toward said table.

12. A pneumatic foundry molding machine comprising a squeeze head at the top of said machine, a squeeze piston assembly operative to move said head downwardly, a table at the bottom of said machine, a clamp piston assembly operative to move said table upwardly, and lock means operative to hold said table in elevated position, said lock means comprising a pair of diametrically opposed lock pins having flattened top surfaces operative in the extended position thereof to underlie said clamp piston assembly.

13. A pneumatic foundry molding machine as set forth in claim 8 wherein the lower portion of said clamp piston is splined, said mechanical lock means comprising a rotatably mounted notched ring receiving said splines in one position and underlying said splines in another position thus to hold said table in elevated position.

14. A foundry molding machine comprising upstanding frame, a pneumatic lift cylinder at the bottom of said frame, a carriage assembly at the top of said frame including a squeeze head carriage and a sand box carriage mounted for shuttling movement back and forth alternately to position the same above said lift cylinder, means operative to elevate said lifht cylinder to assemble a flask and pattern to form a mold box, means operative to shuttle said sand box carriage to a position above such mold box and fill the same with molding sand and then to replace said sand box carriage with said squeeze head carriage, means operative to lock said lift cylinder in such elevated position, said squeeze head carriage including a squeeze piston assembly comprising a cylinder having a fixed partition therein, interconnected pistons on opposite sides of said partition and means to supply fluid under pressure to said pistons within said cylinder operative to urge said pistons toward said mold box to ram a foundry mold therein, means operative to unlock said lift cylinder and then to lower said lift cylinder to draw the pattern from the mold.

15. A foundry molding machine comprising an upstanding frame, a pneumatic lift cylinder at the bottom of said frame, a carriage assembly at the top of said frame including a squeeze head carriage and a sand box carriage mounted for shuttling movement back and forth alternately to position the same above said lift cylinder, means operative to elevate said lift cylinder to assemble a flask and pattern to form a mold box, means operative to shuttle said sand box carriage to a position above such mold box and fill the same with molding sand, and then to replace said mold box carriage with said squeeze head carriage, said squeeze head carriage including a vertically movable squeeze head operative to engage the sand thus positioned in such mold box, and mechanical lock means operative mechanically to lock said lift cylinder in such elevated position firmly to support such mold box as the squeeze head moves against such sand.

16. A foundry molding machine as set forth in claim 15 wherein said mechanical lock means operative mechanically to lock said lift cylinder in elevated position comprises diametrically opposed locking pins including flattened top surfaces operative to move beneath said lift cylinder in such elevated position.

17. A foundry molding machine as set forth in claim 15 wherein said mechanical lock means operative mechanically to lock said lift cylinder in elevated position comprises a locking ring operative in one rotative.position to limit downward movement of said lift cylinder.

References Cited UNITED STATES PATENTS 2,561,266 7/1951 Dietert 164-4 X 2,587,076 2/1952 VersOn et al -219 X 2,852,820 9/1958 Taccone 164-194 X 2,968,846 1/1961 Miller 16417l 3,086,332 4/1963 Wentz 100--219 X 3,111,730 11/1963 Ivarsson 164-184 3,169,285 2/1965 Hatch et al 164-196 J. SPENCER OVERHOLSER, Primary Examiner.

E. MAR, Assistant Examiner. 

